▎ 摘　　要

The theory presented enables calculating the cohesive energy and line energy (the work of formation of the unit border line length) of graphene from the first-principles data, which also yields estimate of the line tension of graphene at zero temperature. Contributions from chemical bonds and dispersion forces have been estimated separately to give a summary value of 16.7 x 10(-10) J m(-1) for the line energy of graphene. The significance of line energy and line tension for nanotube formation is discussed.